The bag it comes in is designed around crushing it to fit into a pack, preserving space for other things.
There is no wrong answer here. Personal preference should determine how you want a pack it. I found the crush bag was very useful in all seasons. It only requires 1 bag and you can determine how much gear you want to have in it. The weight saved in the summer season is from what you don't bring like the extra sleeping bag, bivy, or whatever. The intent of the whole system is it's flexibility. This makes logistics much easier for each GI. Thus the bag for all seasons.
Granite Gear makes many sizes of crush bags. Should you want to choose a different style of crush bag.